"If she did accidentally glance into the lens during filming, the whole scene would have to be re-shot as the invisible wall between the actor and their audience would have been breached."

Despite this, Markle has displayed a lot of confidence and poise since the announcement of her engagement to Prince Harry in November last year.

While the Duchess of Cambridge usually averts her gaze when photographed, Markle tends to look directly at the camera, which makes her persona seem more open and welcoming.

"Although Meghan is the same age as Kate, there is a virtual generational difference in their relationships with the camera," James tells Cosmopolitan.

"Like many young women of the selfie generation, Meghan's habit of doing what is called 'camera courting' (addressing the camera with a direct gaze), suggests a desire to communicate openly and confidently in the way that her peers would do via social media and blogs."

On the other hand, the Duchess of Cambridge often appears more passive in photographs, which perhaps indicates that she has a more reserved personality.

"The fact she has even got behind the camera herself to snap some of her children's official photos suggests a slightly more introverted personality than the camera-confident Meghan," says James.

"She poses beautifully but there is no regular direct communication from her."

According to professor of psychology John Suler, photographs can capture the core of a person's character.